Yes, it is redundant. But if it fits within your budget, and you have the room to store it, so what. A quick look in most people's closets will reveal redundant clothes and shoes. A quick look in many tool boxes will reveal redundant tools. How many screwdrivers does one need? Or hammers, etc.

And for me, I figure if one of my redundant bikes inspires me to get out and do more exercise, then I consider it an "investment" in my health. I rode one of my redundant bikes this afternoon.

And in the case of bicycles, as long as you buy right, we are not talking about budget busting $$$. Its not like a collection of automobiles, or whatever. If it is budget busting, then it is definitely time to stop.

Now on the build, myself, that era Shimano is underwhelming. I would hunt up some high end Suntour from that era instead, like first generation Cyclone or early Superbe. I would be selling off the Shimano, and reinvest the proceeds into some tasty Suntour bits. I've been parting with my early DA and 600 bits myself. I like the later Dura Ace (7400) and 600 (6400) components much better than their earlier versions. Go figure, today's redundant ride has a mix of those two groups.

My wife is very supportive of my bike nonsense, as she has seen what the lack of physical activity did to her parents' mobility in their later years.